Continuous roll coater

ABSTRACT

A ROLL COATER OF THE GRAVURE OR RELATED FLUID APPLYING TYPE WHICH EMPLOYS TURRET EQUIPPED WITH BACKING ROLLS TO ELIMINATE THE MACHINE STOPPAGES USUALLY REQUIRED DURING NORMAL OPERATION.

Sept. 21, 1971 Filed June 19, 1969 CONTINUOUS ROLL COATER 2 Sheets-Sheet 1 FIG.I v

. 25 I/IB i FIG. 2

I7 9 l9 '-l8 ll l4 w I/vv/e/v'm/c EDWIN K. SCHAEUBLE ATT'YS 3,606,861 CONTINUOUS ROLL COATER Edwin K. Schaeuble, Green Bay, Wis., assignor to Paper Converting Machine Company, Inc., Green Bay, Wis. Filed June 19, 1969, Ser. No. 834,749 Int. Cl. Bc N00 US. Cl. 118224 2 Claims ABSTRACT OF THE DISCLOSURE A roll coater of the gravure or related fiuid applying type which employs turret equipped with backing rolls to eliminate the machine stoppages usually required during normal operation.

BACKGROUND AND SUMMARY OF INVENTION The invention is exemplified by a gravure roll coater which offers the industry for the first time a coating unit for continuous operation. The machine eliminates the stoppages usually necessary for changing the backing rolls for diiferent web widths, change of gravure rolls for different coating weights, or changeover to other coating media. As a result, machines which are equipped with flying splice unwinds and rewinds can operate continuously. Therefore, small orders with a relatively short running period of the machine will be as economical as large orders.

DETAILED DESCRIPTION The invention is described in conjunction with an illustrative embodiment, in which FIG. 1 is an end elevation view of the coater, depicted essentially schematically;

FIG. 2 is a fragmentary side elevational view of the inventive coater; and

FIGS. 36 are views of the central portion of FIG. 2 but with the elements thereof in different stages of operation.

The coating and web handling rolls are supported by vertical housing members as at and 11 which are interconnected by rails (not shown). The frames contain all of the mechanical, electrical and hydraulic construction ele ments. When used with a fountainless gravure roll coating system, the coater has a very compact construction. Web threading to and through the coating unit is easy and the coater is accessible from both sides. The drive (provided within the housing 12) is through a longitudinal shaft with interconnected PIV fine adjustment gears. The drive can be used for the upper as well as the lower part of the coater and can be switched over during operation. Alternatively, the machine can also be driven through several separate motors. The coating unit is then driven through a direct current motor. This motor can be used to drive either the upper or lower coating unit part and can be electrically switched over during operation. During the period that the coating unit is changed over, cleaned or during the machine stoppage, separate oil motors drive the coating rolls at a slow speed.

Referring now to FIG. 2, the machine is seen in operation relative to a web W which enters at the lower left and exits at the upper left through a dryer 13. In proceeding upwardly, the web W first encounters idler rolls 14 and 15, thereafter passing between infeed draw rolls 16 and 16'. The first gravure coater is designated generally by the numeral 17 and includes a coating roll 18 operably associated with a suitable doctor 19. The roll 18 is suitably journaled within the frames 10 and 11 and for the backing rolls (when used in the configuration illustrated in FIG. 3), the machine is equipped with a turret United States Patent O Patented Sept. 21, 1971 schematically represented as at 20. The turret 20 carries two backing rolls 21 and 22. As seen in FIG. 2, the lower coater 17 is inoperative. A detour roll mechanism generally designated 23 is next encountered by the web, the detour mechanism 23 including rolls 24 and 25'.

An upper coater generally designated 26 is next encountered, this including a gravure roll 27 with the usual doctor 28 and this is seen to be in pressure engagement with a backing roll 29. The backing roll 29 and a replacement backing roll 30 are provided as part of the upper turret 31 (also depicted schematically).

The showing in FIG. 2 corresponds essentially to that depicted in FIG. 6. The alternate arrangement is seen in FIG. 3 where the lower coater 17 is operational to coat the web W. In proceeding from the arrangement seen in FIG. 3 to that of FIG. 6, the first step involves translating, i.e., moving laterally the turret 20 from the position of FIG. 3 to that of FIG. 4. Thereafter the detour mechanism 23 is changed from the FIG. 4 configuration to that seen in FIG. 5. Lastly, the upper turret 31 is translated from the FIG. 5 condition to that seen in FIG. 6.

Many times changes are required in the operation of a coater because of the width of the web W being changed. To prevent fouling of the rubber covered backing roll, they are usually provided A" less in width than that of the web. By virtue of the turret arrangement herein provided, this changeover is achieved quickly as contrasted to the prior art practices which may have involved several hours. For the simple change of providing a new backing roll, it is merely necessary to translate either the upper or lower coater 26 or 17, as the case may be, and rotate the turret 180 to place the newly selected backing roll in position, thereafter retranslating the turret to operational position. During this time, the machine speed is reduced but no stoppage is necessary. Even during production, the now unused backing roll of the particular turret can be removed and replaced with the backing roll suitable for the next run.

When however, there is a change in the coating weight or the coating medium, the other coater is employed as well.

In FIG. 3, the lower coating unit 17 is seen to be in operation. Before changing to a new coating weight with the same or a new coating medium, the upper coating unit 26 has to be prepared. If necessary, the gravure roll installed will be changed for another one. By using the 180 turning method, a new backing roll 29 is installed for the required web width and put into position. This is done while the lower part of the coater is in operation. A short time before using the upper coating unit 26, the lacquer pumping system is engaged (provided as part of the unit 12) and the gravure roll 27 is driven by means of a servo drive motor (also provided as part of the unit 12). The upper coater 26 is then ready for operation.

Before changing over from the lower coater 17 to the upper coater 26, the machine speed is reduced. The backing roll 22 of the lower coater 17 is withdrawn (see FIG. 4), and a gravure roll 28 associated with the upper coater 26 is switched from the servo drive to the main drive. The lower coater 17 is now driven by means of another servo motor (also provided within the unit 12). At this stage, the detour turret 23 is rotated in counterclockwise direction against a fixed stop to bring about the arrangement depicted in FIG. 5. The detour unit 23 changes the degree of wrap employed in the upper coater 26, providing more support for the Web and avoiding wrinkling through the establishment of a good infeed nip roll arrangement.

After the new web has passed the backing roll 29, the backing roll 29 is brought into working position against the web and gravure roll 28. The machines speed is then resumed. While the upper coater 26 is operating, the

lower coater 17 can be cleaned. After cleaning, the servo motor is disengaged and the lower coater 17 can then be prepared for future job changes. The changeover process can be reversed in a similar manner as the next operation dictates.

It will be appreciated that a wide variety of equipment and applications may utilize the inventive arrangement. This applies to roll coaters, gravure rolls, printers, etc.

I claim:

1. An apparatus for applying a liquid medium to a traveling web comprising a frame, a fluid medium applicator roll journaled for rotation in said frame, means operatively associated with said frame for rotating said applicator roll, means for traveling said web in contact with said applicator roll, a turret mounted on said frame for selective rotation about an axis parallel to the axis of said said applicator roll, said turret rotatably supporting a pair of backing rolls each having an axis parallel to said applicator roll axis, means operably associated with said turret to rotate the same and thereby selectively position the backing rolls thereof to confine said web between one backing roll and said applicator roll whereby a backing roll can be changed to accommodate a different width web without stopping the web.

References Cited UNITED STATES PATENTS 2,494,176 1/ 1950 Howard 118-224X 2,568,446 9/1951 Griflin 118-234X 1,443,164 1/ 1923 Bracken 101-5 2,551,633 5/1951 Preis 1016 FOREIGN PATENTS 251,357 5 1926 England 118224 MERVIN STEIN, Primary Examiner L. MILLSTEIN, Assistant Examiner US. Cl. X.R. l18249 

